The present invention relates generally to layers useful in an imaging apparatus components, for use in electrostatographic, including digital, apparatuses. The layers herein are useful for many purposes including layers for transfix films or transfuse films, and the like. More specifically, the present invention relates to a component outer layer comprising a polymer matrix having small molecules which, upon transfer and/or fixation of a developed image, diffuse through an outer layer of the component so as to promote release of the developed image from the component outer layer. The layers of the present invention may be useful in films used in xerographic machines, especially color machines.
In a typical electrostatographic reproducing apparatus such as electrophotographic imaging system using a photoreceptor, a light image of an original to be copied is recorded in the form of an electrostatic latent image upon a photosensitive member and the latent image is subsequently rendered visible by the application of a developer mixture. One type of developer used in such printing machines is a liquid developer comprising a liquid carrier having toner particles dispersed therein. Generally, the toner is made up of resin and a suitable colorant such as a dye or pigment. Conventional charge director compounds may also be present. The liquid developer material is brought into contact with the electrostatic latent image and the colored toner particles are deposited thereon in image configuration.
The developed toner image recorded on the imaging member can be transferred to an image receiving substrate such as paper via an intermediate transfer member. Alternatively, the developed image can be transferred to an intermediate transfer member from the image receiving member via another transfer member. The toner particles may be transferred by heat and/or pressure to an intermediate transfer member, or more commonly, the toner image particles may be electrostatically transferred to the intermediate transfer member by means of an electrical potential between the imaging member and the intermediate transfer member. After the toner has been transferred to the intermediate transfer member, it can then be transferred to the image receiving substrate, for example by contacting the substrate with the toner image on the intermediate transfer member under heat and/or pressure. Alternatively, the developed image can be transferred to another intermediate transfer member such as a transfix/transfuse or transfer member. A transfix or transfuse member uses heat associated with the transfer member in order to both transfer and fix or fuse the developed image to a copy substrate.
Intermediate transfer members, including transfix or transfuse members, enable high throughput at modest process speeds. In four-color photocopier systems, the transfer member also improves registration of the final color toner image. In such systems, the four component colors of cyan, yellow, magenta and black may be synchronously developed onto one or more imaging members and transferred in registration onto a transfer member at a transfer station.
In electrostatographic printing machines in which the toner image is transferred from the transfix member to the image receiving or copy substrate, it is important that the transfer of the toner particles from the transfix member to the image receiving substrate be substantially 100 percent. Less than complete transfer to the image receiving substrate results in image degradation and low resolution. Completely efficient transfer is particularly important when the imaging process involves generating full color images since undesirable color deterioration in the final colors can occur when the color images are not completely transferred from the transfer member.
Thus, it is desired that the transfix member surface have excellent release characteristics with respect to the toner particles. Conventional materials known in the art for use as transfix members often possess the strength, conformability and electrical conductivity necessary for use as transfix members, but can suffer from poor toner release characteristics, especially with respect to higher gloss image receiving substrates. When heat is associated with a transfer member, such as in the case of a transfix member, the transfix member must also possess good thermal conductivity in addition to superior release characteristics.
In addition, it is desired that the transfix member have sufficient toughness to undergo multiple cycling during use. Moreover, the outer layer of the transfix member should be chemically compatible with toner and with paper that the layer will come in contact with. In known electrophotostatographic machines, diketones are used in paper and toner components. Therefore, it is desired that the transfix outer layer be compatible with diketones and other components of toner and paper.
U.S. Pat. No. 5,361,126 discloses an imaging apparatus including a transfer member including a heater and pressure-applying roller, wherein the transfer member includes a fabric substrate and an impurity-absorbent material as a top layer. The impurity-absorbing material can include a rubber material.
U.S. Pat. No. 5,337,129 discloses an intermediate transfer component comprising a substrate and a ceramer or grafted ceramer coating comprised of integral, interpenetrating networks of haloelastomer, silicon oxide, and optionally polyorganosiloxane.
U.S. Pat. No. 5,340,679 discloses an intermediate transfer component comprised of a substrate and thereover a coating comprised of a volume grafted elastomer, which is a substantially uniform integral interpenetrating network of a hybrid composition of a fluoroelastomer and a polyorganosiloxane.
U.S. Pat. No. 5,456,987 discloses an intermediate transfer component comprising a substrate and a titamer or grafted titamer coating comprised of integral, interpenetrating networks of haloelastomer, titanium dioxide, and optionally polyorganosiloxane.
Some transfix belt configurations are composed of outer layers comprising elastomers. Release fluids have become necessary to promote release of the developed image during transfer and/or fixation of the developed image from the transfer or transfix member to the copy substrate or to another transfer member. These release fluids can contain functionality and can react with the copy substrate and components of the copy substrate, such as paper fibers of paper copy substrates. The result is gelation, which can lead to contamination. The release fluids can also react with other transfer members that they may come in contact with during transfer. The release fluids can subsequently react with other components of the subsystem, resulting in several adverse effects from the contamination of the subsystem with these oils. One possible result is an accelerated component failure due to severe contamination. This undesirable result can occur as early as several thousand prints.
Therefore, it is desired to provide a transfer or transfix member that provides for adequate release of the developed image upon transfer and/or fixation, without the drawbacks of a release agent which may react adversely with copy substrate materials, other transfer members and subsystem members, thereby contaminating the entire system. It is also desired to provide a transfix member which has an outer layer which does not react adversely with the chemical components of paper and/or toner.
The present invention provides, in embodiments: a component film having a surface layer and a polymer matrix layer comprising a polymer and small molecules, the polymer matrix layer designed to allow the small molecules to diffuse through the polymer matrix layer to the surface layer upon the application of pressure or heat to the component film.
The present invention further provides, in embodiments: a component film having a surface layer and polymer matrix layer comprising a polymer and small molecules, the polymer matrix layer designed to allow the small molecules to diffuse through the polymer matrix layer to the surface layer upon the application of pressure or heat to the component film, wherein the polymer is a functional polydimethylsiloxane polymer and the small molecules are non-functional silicone oligomers.
In addition, the present invention provides, in embodiments: a component film having a surface layer and a polymer matrix layer comprising a polymer and small molecules, the polymer matrix layer designed to allow the small molecules to diffuse through the polymer matrix layer to the surface layer upon the application of pressure or heat to the component film, wherein the polymer is a silicone polymer and the small molecules are oligomers having from about 4 to about 30 cyclic units.